Heat pipes are heat transfer devices to move heat from a hot source (referred to as an “evaporator”) to a cold sink (referred to as a “condenser”). FIG. 1 illustrates the cross section of a conventional heat pipe 100. Referring to FIG. 1, heat flow occurs via evaporation of the heat pipe working fluid at the evaporator end 101; the heat absorbed is used to convert liquid into vapor (see arrows near evaporator end 101). This hot vapor flows through the pipe center (see arrows in middle of heat pipe 100) and condenses at the condenser (cold) end 102 where it rejects the heat (see arrows near condenser end 102). A wick structure 103 lining the inside of heat pipe 100 pulls the condensed liquid back to evaporator 101 (see arrows in wick structure 103 directed to evaporator 101) to complete the closed cycle. Heat pipe 100 utilizes capillary action in an internal wick structure 103 to drive liquid circulation. As a result, the length of conventional heat pipes is limited by the capillary pressure generated in the heat pipe wick beyond which the wick cannot provide sufficient liquid to the evaporator. Consequently, conventional heat pipes cannot transport heat over very long distances (at high enough heat flow rates) since the wick pressure is not sufficient to pump liquid condensate back to the evaporator. Furthermore, conventional heat pipe architectures do not easily lend themselves to very thin and slender shapes which may expand the potential applications of heat pipes.